US President Joe Biden celebrated his 81st birthday on Monday, marking a significant milestone in his life. However, as the president's age becomes a topic of concern, discussions about the succession plan in the event of his death while running for reelection have emerged.

Biden's age has been a contentious issue during his presidency, with recent polls indicating that voters are worried about his ability to serve effectively. These concerns have gained momentum as Biden gears up for a challenging reelection campaign next year.

In light of his advancing age, questions naturally arise about what would happen if a sitting president were to pass away while seeking a second term. The United States has a well-defined presidential order of succession outlined in the Constitution and the Presidential Succession Act of 1947, which dictates that the vice president would assume the presidency.

In this scenario, Vice President Kamala Harris would become the next president, making history as the first female president and the second Black president of the United States. From an electoral standpoint, Harris would also replace Biden as the Democratic presidential candidate. However, his untimely demise would likely open the door for other Democrats to enter the 2024 race.

As for the practical implications, the deadline for filing to run for the presidency varies from state to state and party to party. While many states' deadlines have already passed, adjustments would need to be made by state election officials to accommodate new candidates entering the race.

In the case of a president passing away during the primary season, some states might choose to postpone their scheduled primaries, as was seen during the COVID-19 pandemic when more than a dozen states rescheduled their primaries or expanded mail-in voting options.

In the event that a sitting president were to pass away after the primaries but before their party's convention, the remaining presidential candidates would have to make a compelling case to every state delegation at the convention, vying for the party's nomination.

Lastly, if a president were to pass away after securing their party's nomination but before Election Day, both the Democratic and Republican parties have established guidelines for selecting an alternate candidate. These guidelines grant the parties the authority to vote on another nominee.

While the possibility of a sitting president's death during a reelection campaign is somber to consider, the United States has established mechanisms to ensure a smooth transition of power. As President Joe Biden commemorates his birthday, the nation reflects on the future and the potential scenarios that may unfold in the coming years.